The present invention relates generally to electronic display guidance indicators, and more particularly, to an electronic liquid crystal display indicator capable of displaying more than one type of guidance indicator in the same unit.
An example of such displays are electronic flight indicators which are required on most aircraft, to inform the pilot and, if applicable, the co-pilot of the aircraft, of various information to assist in flying the aircraft. Military aircraft, commercial aircraft and even personally owned airplanes include electronic flight indicators in the instrument panels of the aircraft. Two common electronic flight indicators are: a horizontal situation indicator ("HSI"); and, an attitude direction indicator ("ADI"). For many years HSI and ADI have consisted of electro-mechanical devices which use several internal gears powered by an electric motor(s) to drive the displays seen on the screen.
Most military and commercial aircraft of today have a standard aircraft instrument panel dimension for each flight indicator. This is sometimes referred to as an ARINC cutout. In certain aircraft the ARINC cutout for an ADI or HSI has already been predetermined by industry standards.
Known flight indicators have maintained one function for each indicator unit. For example, an HSI unit has been known to be a unique display indicator in comparison to an ADI unit. Due to the complexity involved in generating a particular display on the viewing screen of such a unit, known display indicators have been limited to just one type of display Therefore, HSI units have been separate from ADI units which also have been separate from radar units, etc. For a variety of reasons it would be advantageous to have a multifunctional display indicator. First, purchasing and inventory management would be simpler since there would be less part numbers to have in stock. Second, replacement of a unit would be faster and more reliable especially in a stressful situation such as during war. Instead of potential mixups with part numbers, one unit would serve two or more functions. Third, instead of technicians having to learn to repair several different display indicators they can learn the workings of just one.
The present invention comprises an electronic liquid crystal display indicator having self-contained multiple functions. The indicator of the present invention is capable of use as an HSI unit and as an ADI unit. It may also be adapted to offer radar or other functions. By use of a unique adapter cable which is connected to the display indicator and is connected to existing aircraft wiring, an HSI display may be viewed on the unit. By use of a second unique adapter cable which also connects to existing aircraft wiring an ADI display may be visible on the unit. The unit recognizes the incoming signals from the existing aircraft wiring (from various sensors on the aircraft known to those of ordinary skill in the art) connected to the unique adapter cable to determine whether an HSI display or an ADI display is to be generated.
To help maintain the size of the unit to reside in a standard ARINC cutout, the different indicator displays (HSI or ADI, for example) of the present invention preferably use some of the same incoming signals. By sharing signals less space is needed for the additional hardware that would be required if the signals for each indicator display were all unique. The present invention may also utilize surface mount electronic components on circuit boards to conserve space. Very large scale integration ("VLSI") may also be used incorporating programmable logic devices within the unit. Furthermore, a unique interior layout of all components inside the unit enables multifunctional capability within space limitations set by the aircraft industry. The present invention also comprises a graphics processor which drives the display viewed by the operator.
Internal software within the unit of the present invention first determines whether the incoming signals from the existing aircraft wiring are HSI signals or ADI signals. The software then facilitates the reading of all signals coming into the unit from the harness or cable. The software assembles the signals into packets of information and sends these packets to the graphics processor. The packets of information tell the graphics processor to display either an ADI or an HSI. The graphics processor then facilitates the "drawing" of the display on the viewing area of the LCD glass providing a graphical representation of the signals.
Obvious modifications to the present invention are expected to fall within the scope of the claims of the present invention The above stated and other advantages of the present invention will be better understood from the following description of the drawings and detailed description of the preferred embodiment(s).